After further investigation, I found that this ‘overwritehost’ statment is indeed causing problems to others (Running Nextcloud on HTTPS mode behind a Reverse Proxy) and that it could be changed in the APP UI configuration page in the Enviromental variables section. I was able to connect sucessfully with the following config:
Nextcloud config in Truenas:
Host: blank
Enviromental variables :
OVERWRITEHOST
my domain :30027
OVERWRITECLIURL
http://my domain:30027 (I’m not sure what this does, I’ll try to remove it)
Web Port:
30027
Certificate:
‘truenas_default’ Certificate